Methods for power headroom reporting, resource allocation, and power control

ABSTRACT

Methods and apparatuses are provided for reporting power headroom for a UE. At least one of power control information associated with a PUSCH transmission in a subframe and power control information associated with a PUCCH transmission in the subframe is received. One of a first power headroom information and a second power headroom information is conditionally generated. One of the first power headroom information and the second power headroom information is conditionally transmitted. If the UE transmits the PUSCH without the PUCCH in the subframe, the second power headroom information is generated by subtracting the transmit power for the PUSCH transmission and a transmit power for a PUCCH from the maximum transmit power of the UE in the subframe based on the power control information associated with the PUSCH transmission and power control information associated with the latest PUCCH transmission.

PRIORITY

This application is a Continuation Application of U.S. patentapplication Ser. No. 12/902,903, filed in the U.S. Patent and TrademarkOffice on Oct. 12, 2010, which claims priority under 35 U.S.C. §119(a)to a Korean Patent Application filed in the Korean Intellectual PropertyOffice on Oct. 9, 2009, and assigned Serial No. 10-2009-0096259 and to aKorean Patent Application filed in the Korean Intellectual PropertyOffice on Apr. 5, 2010, and assigned Serial No. 10-2010-0031072, thecontents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to power headroom reporting and,more particularly, to methods for resource allocation and power controlbased on power headroom reporting.

2. Description of the Related Art

In recent years, in order to achieve high-speed data transmission overradio channels of mobile communication systems, significant researchefforts have been made to develop technologies related to OrthogonalFrequency Division Multiplexing (OFDM) and Single Carrier-FrequencyDivision Multiple Access (SC-FDMA). For example, the Long Term Evolution(LTE) system, which is regarded as a next-generation mobilecommunication system, employs OFDM for downlink and SC-FDMA for uplink.However, since OFDM has a high Peak-to-Average Power Ratio (PAPR), alarge back-off is required for the input to the power amplifier to avoidnonlinear signal distortion, which lowers the maximum transmit power.This results in low power efficiency. The back-off sets the maximumtransmit power to a level lower than the maximum power of the poweramplifier, in order to ensure linearity of the transmit signal. Forexample, when the maximum power of the power amplifier is 23 dBm and theback-off is 3 dBm, the maximum transmit power becomes 20 dBm. OFDMA doesnot have any significant drawbacks as a downlink multiplexingtechnology, because the transmitter is located in a base station thathas no power limitations. However, OFDMA has significant drawbacks, asan uplink multiplexing technology, because the transmitter is located inuser equipment (such as a mobile terminal), which has severe powerlimitations. These limitations may reduce the terminal transmit powerand service coverage. Consequently, SC-FDMA has been employed as uplinkmultiplexing technology for LTE, which is proposed by 3GPP (3rdGeneration Partnership Project) as a fourth generation mobilecommunication system.

High-speed data transmission is required to provide diverse multimediaservices in advanced wireless communication environments. In particular,considerable effort has been made to develop Multiple-Input andMultiple-Output (MIMO) technology for high-speed data transmission. MIMOemploys multiple antennas to increase channel capacity within givenfrequency resource limitations. In scattering environments, use ofmultiple antennas may produce a channel capacity proportional to thenumber of antennas. Precoding is necessary in order to efficientlytransmit data through MIMO. Precoding rules may be represented in amatrix form (precoding matrices), and a set of pre-defined precodingmatrices is referred to as a codebook. In LTE Advanced (LTE-A), MIMObased on precoding matrices is recommended as a primary uplinktechnology enabling performance enhancement in both single-user andmulti-user environments.

However, several problems exist when using an LTE-A system. First, theLTE-Advanced system allows simultaneous transmission over a PhysicalUplink Shared Channel (PUSCH) and a Physical Uplink Control Channel(PUCCH). When a mobile terminal capable of simultaneous transmissionsends a power headroom report containing only PUSCH transmit powerinformation to a serving base station, the base station may adjust anamount of allocated PUSCH transmit power and other resources than areactually needed to the mobile terminal. In other words, cellinterference may be increased due to excessive transmit power, orterminal link performance may be lowered due to insufficient transmitpower.

Second, when a base station in an LTE-Advanced system schedules a MIMOtransmission for a mobile terminal using the LTE scheduler, the basestation may use the Sounding Reference Signal (SRS) from the mobileterminal to select precoding matrices that maximize uplink channelcapacity. In MIMO transmission, one codeword may be mapped totransmission layers in different channel environments. However, atransmit power of each layer may be not adjusted using precodingmatrices alone.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above problems, andthe present invention provides a power headroom reporting method that issuitable to cases in which transmissions over both PUCCH and PUSCH areallowed in the same subframe, and methods for resource allocation andpower control using the same.

In accordance with an embodiment of the present invention, a method isprovided for reporting power headroom for a User Equipment (UE). Atleast one of power control information associated with a PUSCHtransmission in a subframe and power control information associated witha PUCCH transmission in the subframe is received. One of a first powerheadroom information and a second power headroom information isconditionally generated. The first power headroom information isgenerated by subtracting a transmit power for the PUSCH transmissionfrom a maximum transmit power of the UE in the subframe based on the atleast one of the power control information associated with the PUSCHtransmission and the power control information associated with the PUCCHtransmission. The second power headroom information is generated bysubtracting the transmit power for the PUSCH transmission and a transmitpower for the PUCCH transmission from the maximum transmit power of theUE in the subframe based on the power control information associatedwith the PUSCH transmission and the power control information associatedwith the PUCCH transmission. One of the first power headroom informationand the second power headroom information is conditionally transmitted.If the UE transmits the PUSCH without the PUCCH in the subframe, thesecond power headroom information is generated by subtracting thetransmit power for the PUSCH transmission and a transmit power for aPUCCH from the maximum transmit power of the UE in the subframe based onthe power control information associated with the PUSCH transmission andpower control information associated with the latest PUCCH transmission.

In accordance with another embodiment of the present invention, anapparatus is provided for reporting power headroom. The apparatusincludes a UE. The UE is configured to perform reception of at least oneof power control information associated with a PUSCH transmission andpower control information associated with a PUCCH transmission in thesubframe. The UE is also configured to perform conditional generation ofone of a first power headroom information and a second power headroominformation. The first power headroom information is generated bysubtracting a transmit power for the PUSCH transmission from a maximumtransmit power of the UE in the subframe based on the at least one ofthe power control information associated with the PUSCH transmission andthe power control information associated with the PUCCH transmission.The second power headroom information is generated by subtracting thetransmit power for the PUSCH transmission and a transmit power for thePUCCH transmission from the maximum transmit power of the UE in thesubframe based on the power control information associated with thePUSCH transmission and the power control information associated with thePUCCH transmission. The UE is further configured to perform conditionaltransmission of one of the first power headroom information and thesecond power headroom information. If the UE transmits the PUSCH withoutthe PUCCH in the subframe, the second power headroom information isgenerated by subtracting the transmit power for the PUSCH transmissionand a transmit power for a PUCCH from the maximum transmit power of theUE in the subframe based on the power control information associatedwith the PUSCH transmission and power control information associatedwith the latest PUCCH transmission.

In accordance with another embodiment of the present invention, a methodis provided for receiving power headroom from a UE. At least one ofpower control information associated with a PUSCH transmission in asubframe and power control information associated with a PUCCHtransmission in the subframe is transmitted to the UE. One of a firstpower headroom information and a second power headroom information isconditionally received from the UE. The first power headroom informationis generated by subtracting a transmit power for the PUSCH transmissionfrom a maximum transmit power of the UE in the subframe based on the atleast one of the power control information associated with the PUSCHtransmission and the power control information associated with the PUCCHtransmission. The second power headroom information is generated bysubtracting the transmit power for the PUSCH transmission and a transmitpower for the PUCCH transmission from the maximum transmit power of theUE in the subframe based on the power control information associatedwith the PUSCH transmission and the power control information associatedwith the PUCCH transmission. If the UE transmits the PUSCH withoutthePUCCH in the subframe, the second power headroom information isgenerated by subtracting the transmit power for the PUSCH transmissionand a transmit power for a PUCCH from the maximum transmit power of theUE in the subframe based on the power control information associatedwith the PUSCH transmission and power control information associatedwith the latest PUCCH transmission.

In accordance with another embodiment of the present invention, anapparatus for receiving power headroom is provided. The apparatusincludes a transmitter configured to transmit, to a UE, at least one ofpower control information associated with a PUSCH transmission and powercontrol information associated with a PUCCH transmission in thesubframe. The apparatus also includes a receiver configured toconditionally receive one of a first power headroom information and asecond power headroom information from the UE. The first power headroominformation is generated by subtracting a transmit power for the PUSCHtransmission from a maximum transmit power of the UE in the subframebased on the at least one of the power control information associatedwith the PUSCH transmission and the power control information associatedwith the PUCCH transmission. The second power headroom information isgenerated by subtracting the transmit power for the PUSCH transmissionand a transmit power for the PUCCH transmission from the maximumtransmit power of the UE in the subframe based on the power controlinformation associated with the PUSCH transmission and the power controlinformation associated with the PUCCH transmission. If the UE transmitsthe PUSCH without the PUCCH in the subframe, the second power headroominformation is generated by subtracting the transmit power for the PUSCHtransmission and a transmit power for a PUCCH from the maximum transmitpower of the UE in the subframe based on the power control informationassociated with the PUSCH transmission and power control informationassociated with the latest PUCCH transmission.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the present invention will be moreapparent from the following detailed description in conjunction with theaccompanying drawings, in which:

FIG. 1 is a diagram illustrating power headroom reporting in the LTEsystem where PUSCH transmission and PUCCH transmission are conducted indifferent subframes according to an embodiment of the present invention;

FIG. 2 is a diagram illustrating power headroom reporting according to afirst embodiment of the present invention;

FIG. 3 is a diagram illustrating power headroom reporting according tothe first embodiment of the present invention;

FIG. 4 is a flow chart illustrating a procedure for power headroomreporting performed by a mobile terminal according to the firstembodiment of the present invention;

FIG. 5 is a flow chart illustrating a procedure for power headroomreporting performed by a base station according to the first embodimentof the present invention;

FIG. 6 is a diagram illustrating power headroom reporting according to asecond embodiment of the present invention;

FIG. 7 is a flow chart illustrating a procedure for power headroomreporting performed by a mobile terminal according to the secondembodiment of the present invention;

FIG. 8 is a flow chart illustrating a procedure for power headroomreporting performed by a base station according to the second embodimentof the present invention;

FIG. 9 is a diagram illustrating power headroom reporting according to athird embodiment of the present invention;

FIG. 10 is a flow chart illustrating a procedure for power headroomreporting performed by a mobile terminal according to the thirdembodiment of the present invention;

FIG. 11 is a flow chart illustrating a procedure for per-layer powercontrol performed by a base station according to a fifth embodiment ofthe present invention;

FIG. 12 is a flow chart illustrating a procedure for per-layer powercontrol performed by a base station according to a sixth embodiment ofthe present invention; and

FIG. 13 is a diagram illustrating power headroom reporting according toa seventh embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Hereinafter, embodiments of the present invention are described indetail with reference to the accompanying drawings. The same referencesymbols are used throughout the drawings to refer to the same or similarparts. Detailed descriptions of well-known functions and structuresincorporated herein may be omitted in order to avoid obscuring thesubject matter of the present invention. Particular terms may be definedto describe the invention in the best manner. Accordingly, the meaningsof specific terms or words used in the specification and the claims arenot limited to the literal or commonly employed sense, but are to beconstrued in accordance with the spirit of the invention.

The description of embodiments of the present invention is focused on awireless communication system based on OFDM, in particular, on the ThirdGeneration Partnership Project (3GPP) Evolved Universal TerrestrialRadio Access (E-UTRA), or LTE system or an Advanced E-UTRA (or LTE-A)system. However, it should be apparent to those skilled in the art thatthe subject matter of the present invention is applicable to othercommunication systems having similar technical backgrounds and channelstructures with or without minor changes or modifications.

In the LTE system, uplink power control may be described in terms ofPUSCH power control, PUCCH power control, and power headroom reporting.

PUSCH Power Control refers to event-based power control is applied toPUSCH in the LTE uplink. In other words, when using PUSCH, it isunnecessary to periodically send Transmit Power Control (TPC) commands.The transmit power δ_(PUSCH)(i) for PUSCH transmission in a subframe iis given according to Equation 1:P _(PUSCH)(i)=min{P _(CMAX), 10 log₁₀(M _(PUSCH)(i))+P _(O) _(—)_(PUSCH)(j)+α(j)·PL+Δ _(TF)(i)+f(i)}[dBm]  (1)

In Equation 1, P_(CMAX) denotes the maximum transmit power according tothe power class of a mobile terminal or User Equipment (UE); andM_(PUSCH)(i) denotes PUSCH resource assignment expressed as a number ofResource Blocks (RB) valid for subframe i. Equation 1 shows that thetransmit power for PUSCH transmission of a mobile terminal or UEincreases in proportion to M_(PUSCH)(i). In Equation 1, Path Loss (PL)denotes downlink path-loss estimate calculated at the terminal; and α(j)is a scaling factor that is determined by higher layers in considerationof mismatch between uplink path-loss and downlink path-loss due to cellconfiguration.

P_(O) _(—) _(PUSCH) of Equation 1 may be given by Equation 2, asfollows:P _(O) _(—) _(PUSCH)(j)=P _(O) _(—) _(NOMINAL) _(—) _(PUSCH)(j)+P _(O)_(—) _(UE) _(—) _(PUSCH)(j)  (2)

In Equation 2, P_(O) _(—) _(NOMINAL) _(—) _(PUSCH)(j) is a cell-specificparameter provided by higher layers; and P_(O) _(—) _(UE) _(—)_(PUSCH)(j) is a UE-specific parameter provided by Radio ResourceControl (RRC) signaling, as follows:

Δ_(TF)(i) of Equation 1 is a parameter for a Modulation and CodingScheme (MCS) or a Transport Format (TF) compensation, and is given byEquation 3, as follows:

$\begin{matrix}{{\Delta_{TF}(i)} = \{ \begin{matrix}{10{\log_{10}( {2^{{{MPR}{(i)}} \cdot K_{S}} - 1} )}} & {{{for}\mspace{14mu} K_{S}} = 1.25} \\0 & {{{for}\mspace{14mu} K_{S}} = 0}\end{matrix} } & (3)\end{matrix}$

In Equation 3, K_(s) is a cell-specific parameter provided by RRCsignaling.

MPR(i) is given by Equation 4, as follows:MPR(i)=TBS(i)/(M _(PUSCH)(i)·N ^(RB) _(sc)·2N ^(UL) _(symb))  (4)

In Equation 4, TBS(i) denotes the size of the transport block insubframe i, and the denominator (M_(PUSCH)(i)·N^(RB) _(sc)·2N^(UL)_(symb)) denotes the number of Resource Elements (RE) in subframe i.Namely, MPR(i) given by Equation 4 indicates the number of informationbits per resource element. If K_(s)=0, MPR(i)=0, and hence MCScompensation is not considered. If K_(s)=1.25, 80 percent of the uplinkchannel (1/K_(s)=0.8) is MCS-compensated.

f(i) of Equation 1 indicates current PUSCH power control adjustment, andis given by Equation 5, as follows:f(i)=f(i−1)+δ_(PUSCH)(i−K _(PUSCH))  (5)

δ_(PUSCH) is a UE-specific parameter known as a TPC command provided bythe base station through a Physical Downlink Control Channel (PDCCH).K_(PUSCH) of δ_(PUSCH)(i−K_(PUSCH)) indicates presence of a time gapbetween δ_(PUSCH) reception and δ_(PUSCH) application to thetransmission subframe. δ_(PUSCH) dB accumulated values signaled on PDCCHwith Downlink Control Information (DCI) format 0 are −1, 0, 1 and 3.δ_(PUSCH) dB accumulated values signaled on PDCCH with DCI format 3/3Aare −1 and 1 or −1, 0, 1 and 3.

In addition to use of δ_(PUSCH) accumulated values as in Equation 5,δ_(PUSCH) absolute values may be used as in Equation 6, as follows:f(i)=δ_(PUSCH)(i−K _(PUSCH))  (6)

δ_(PUSCH) dB absolute values signaled on PDCCH with DCI format 0 are −4,−1, 1 and 4.

PUCCH Power Control: The transmit power P_(PUCCH)(i) for PUCCHtransmission in subframe i is given by Equation 7:P _(PUCCH)(i)=min{P _(CMAX) , P _(O) _(—) _(PUCCH) +PL+h(n _(CQI) , n_(HARQ))+Δ_(F) _(—) _(PUCCH)(F)+g(i)}[dBm]  (7)

In Equation 7, P_(CMAX) denotes the maximum transmit power according tothe power class of the mobile terminal (or UE). Δ_(F) _(—) _(PUCCH)(F)values correspond to PUCCH formats (F) and are provided by RRCsignaling.

P_(O) _(—) _(PUCCH) is defined by Equation 8:P _(O) _(—) _(PUCCH) =P _(O) _(—) _(NOMINAL) _(—) _(PUCCH) +P _(O) _(—)_(UE) _(—) _(PUCCH)  (8)

In Equation 8, P_(O) _(—) _(NOMINAL) _(—) _(PUCCH) is a cell-specificparameter provided by higher layers, and P_(O) _(—) _(UE) _(—) _(PUCCH)is a UE-specific parameter provided by RRC signaling.

h(n_(CQI), n_(HARQ)) is given by Equation 9, and is a PUCCH formatdependent value, as follows:

$\begin{matrix}{\mspace{79mu}{{{{h( {n_{CQI},n_{HARQ}} )} = 0},\mspace{20mu}{{for}\mspace{14mu}{PUCCH}\mspace{14mu}{format}\mspace{14mu} 1},{1a},{1b}}\mspace{20mu}{{h( {n_{CQI},n_{HARQ}} )} = \{ {{\begin{matrix}{10{\log_{10}( \frac{n_{CQI}}{4} )}} & {{{if}\mspace{14mu} n_{CQI}} \geq 4} \\0 & {otherwise}\end{matrix}\mspace{20mu}{for}\mspace{14mu}{PUCCH}\mspace{14mu}{format}\mspace{14mu} 2},{2a},{{2b{h( {n_{CQI},n_{HARQ}} )}} = \{ {\begin{matrix}{10{\log_{10}( \frac{n_{CQI} + n_{HARQ}}{4} )}} & {{{{if}\mspace{14mu} n_{CQI}} + n_{HARQ}} \geq 4} \\0 & {otherwise}\end{matrix}{for}\mspace{14mu}{PUCCH}\mspace{14mu}{format}\mspace{14mu} 2} }} }}} & (9)\end{matrix}$

n_(CQI), corresponds to the number of information bits for the ChannelQuality Indication (CQI), and n_(HARQ) corresponds to the number of bitsfor the Hybrid Automatic Repeat reQuest (HARQ). Here, PUCCH format 1, 1aor 1b is used for ACK/NACK. Particularly, PUCCH format 1 a may be usedfor calculating h(n_(CQI), n_(HARQ)) according to an embodiment of thepresent invention.

g(i) denotes the current PUCCH power control adjustment and is given byEquation 10:g(i)=g(i−1)+δ_(PUCCH)(i−K _(PUCCH))  (10)

δ_(PUCCH) is a UE-specific parameter known as a TPC command provided bythe base station through PDCCH. K_(PUCCH) of δ_(PUCCH)(i−K_(PUCCH))indicates presence of a time gap K_(PUCCH) between the time of δ_(PUCCH)reception and the time of δ_(PUCCH) application to the transmissionsubframe.

The base station of the LTE system receives a Power Headroom Report(PHR) from the mobile terminal and uses PHR to schedule the mobileterminal by assigning the transmit power for PUSCH transmission andM_(PUSCH)(i) in subframe i. Here, M_(PUSCH)(i) denotes PUSCH resourcesallocated in subframe i and is represented as a number of resourceblocks.

FIG. 1 is a diagram illustrating power headroom reporting in the LTEsystem where PUSCH transmission and PUCCH transmission are conducted indifferent subframes according to an embodiment of the present invention.

In the LTE system of FIG. 1, in order to avoid violating the SingleCarrier (SC) property, PUCCH transmission and PUSCH transmission must beconducted in different subframes. Hence, as defined in Equation 11, thepower headroom PH_(PUSCH), to be reported by the mobile terminal to thebase station, indicates the difference between the maximum transmitpower according to the power class of the mobile terminal (P_(CMAX)) andthe PUSCH transmit power calculated at subframe i (P_(PUSCH)(i)), asfollows:PH _(PUSCH)(i)=P _(CMAX) −P _(PUSCH)(i)[dB]  (11)

Events triggering power headroom reporting may include a significantchange in path-loss estimation and expiration of a preset timer value.

First to third embodiments of the present invention, which are relatedto power headroom reporting, as described as follows.

First Embodiment of the Present Invention

FIG. 2 is a diagram illustrating power headroom reporting according tothe first embodiment of the present invention.

Referring to FIG. 2, in a case where the LTE-Advanced system allowstransmissions over both PUSCH and PUCCH in the same subframe, inresponse to occurrence of an event requesting power headroom (PH)reporting, the mobile terminal may report PH_(PUSCH) andPH_(PUSCH+PUCCH) to the base station using Equation 12:PH _(PUSCH+PUCCH)(i)=P _(CMAX) −P _(PUSCH)(i)−P _(PUCCH)(i)[dB]PH _(PUSCH)(i)=P _(CMAX) −P _(PUSCH)(i)[dB]  (12)

Here, an event requesting power headroom reporting may correspond toreception of an external signal requesting power headroom reporting ordetection of a predefined event requesting power headroom reporting,such as detection of a significant change in path-loss estimation,expiration of a preset timer value, or expiration of a preset period.

As in Equation 12, PH_(PUSCH+PUCCH) 206 is given by subtracting thetransmit power P_(PUSCH)(i) 204 for PUSCH transmission 202 calculated insubframe i and the transmit power P_(PUCCH)(i) 203 for PUCCHtransmission 201 calculated in subframe i from the maximum transmitpower according to the power class of the mobile terminal (P_(CMAX)).PH_(PUSCH) 205 is given by subtracting the transmit power P_(PUSCH)(i)204 for PUSCH transmission 202 calculated in subframe i from the maximumtransmit power according to the power class of the mobile terminal(P_(CMAX)). In FIG. 2, subframe number i is set to 4.

FIG. 3 is a diagram illustrating power headroom reporting according tothe first embodiment of the present invention.

Referring to FIG. 3, in a case where the LTE-Advanced system allowstransmissions over both PUSCH and PUCCH in the same subframe, inresponse to an occurrence of an event for requesting power headroomreporting, the mobile terminal may report PH_(PUSCH) 306 andPH_(PUSCH+PUCCH) 307 to the base station using Equation 12.PH_(PUSCH+PUCCH) 307 is determined by subtracting the transmit powerP_(PUSCH)(i) 305 for PUSCH transmission 302 calculated in subframe i andthe transmit power P_(PUCCH)(i) 304 for PUCCH transmission 301calculated in subframe i from the maximum transmit power according tothe power class of the mobile terminal (P_(CMAX)). In FIG. 2, thetransmit power P_(PUSCH) 204 for PUSCH transmission 202 and the transmitpower P_(PUCCH) 203 for PUCCH transmission 201 are both calculated insubframe 4. Meanwhile, in FIG. 3, the transmit power P_(PUCCH) 304 forPUCCH transmission 301 is calculated in subframe 1, and the transmitpower P_(PUSCH) 305 for PUSCH transmission 302 is calculated in subframe4. As a PUCCH transmission (indicated by reference symbol 303) is notpresent in subframe 4, the transmit power P_(PUCCH) 304 for the latestPUCCH transmission 301 is utilized for power headroom reporting insubframe 4. PH_(PUSCH) 306 is determined by subtracting the transmitpower P_(PUSCH)(i) 305 for PUSCH transmission 302 calculated in subframei from the maximum transmit power according to the power class of themobile terminal (P_(CMAX)). In FIG. 3, subframe number i is set to 4.

FIG. 4 is a flow chart illustrating a procedure for power headroomreporting performed by the mobile terminal according to the firstembodiment of the present invention.

Referring to FIG. 4, the mobile terminal determines whether PUSCHtransmission and PUCCH transmission are allowed to occur in the samesubframe, in step 401. Permission for parallel transmission over bothPUSCH and PUCCH in the same subframe may be indicated by signals fromhigher layers or the base station.

When PUSCH transmission and PUCCH transmission are not allowed in thesame subframe (i.e., when PUSCH transmission and PUCCH transmission mustoccur in different subframes), the mobile terminal determines whether anevent requesting PH_(PUSCH) reporting has been generated, in step 407.When an event requesting PH_(PUSCH) reporting has been generated, themobile terminal reports PH_(PUSCH) to the base station according toEquation 11, in step 408. When an event requesting PH_(PUSCH) reportinghas not been generated, the mobile terminal waits for generation of suchan event.

When PUSCH transmission and PUCCH transmission are allowed to occur inthe same subframe, the mobile terminal stores information regarding thetransmit power P_(PUCCH) for each PUCCH transmission, in step 402.

The mobile terminal determines whether an event requestingPH_(PUSCH+PUCCH) reporting has been generated, in step 403. When anevent requesting PH_(PUSCH+PUCCH) reporting has not been generated, themobile terminal returns to step 402.

When an event requesting PH_(PUSCH+PUCCH) reporting is generated, themobile terminal determines whether PUCCH transmission is present insubframe i, in step 404.

When PUCCH transmission is present in subframe i, the mobile terminalreports PH_(PUSCH+PUCCH) and PH_(PUSCH) to the base station using thetransmit power P_(PUCCH)(i) for PUCCH transmission in subframe i, instep 405.

When PUCCH transmission is not present in subframe i, the mobileterminal reports PH_(PUSCH+PUCCH) and PH_(PUSCH) to the base stationusing the stored transmit power P_(PUCCH) for the latest PUCCHtransmission, in step 409.

FIG. 5 is a flow chart illustrating a procedure for power headroomreporting performed by the base station according to the firstembodiment of the present invention.

Referring to FIG. 5, the base station determines whether the mobileterminal is allowed to conduct both PUSCH transmission and PUCCHtransmission in the same subframe, in step 501.

When the mobile terminal is allowed to conduct PUSCH transmission andPUCCH transmission in the same subframe, the base station receivesPH_(PUSCH+PUCCH) and PH_(PUSCH) from the mobile terminal in a subframewhere a corresponding event is generated, in step 502.

The base station determines whether both PUSCH transmission and PUCCHtransmission are present in a scheduled subframe at which a PUCCHtransmission from the mobile terminal is present, in step 503.

When only PUSCH transmission is present in the scheduled subframe atwhich a PUCCH transmission from the mobile terminal is present, the basestation assigns MCS and M_(PUSCH) to the mobile terminal using reportedPH_(PUSCH), in step 504.

When both PUSCH transmission and PUCCH transmission are present in thescheduled subframe at which a PUCCH transmission from the mobileterminal is present, the mobile terminal conducts PUSCH transmission andPUCCH transmission in the scheduled subframe, in step 508.

The base station assigns MCS and M_(PUSCH) to the mobile terminal usingthe reported PH_(PUSCH+PUCCH), in step 509.

When it is determined that the mobile terminal is not allowed to conductPUSCH transmission and PUCCH transmission in the same subframe at step501, the base station receives PH_(PUSCH) from the mobile terminal, instep 506, and assigns MCS and M_(PUSCH) to the mobile terminal in ascheduled subframe using reported PH_(PUSCH), in step 507.

Second Embodiment of the Present Invention:

According to the first embodiment of the present invention, when a PUCCHtransmission is not present in subframe 4, the stored transmit powerP_(PUCCH) for the latest PUCCH transmission in an earlier subframe isutilized. For example, in FIG. 3, the transmit power for PUCCHtransmission 301 in subframe 1 is used in subframe 4. However,h(n_(CQI), n_(HARQ)) given by Equation 9 may have different valuesaccording to PUCCH formats. If the format expected by the base stationis different from that actually used by the mobile terminal, a problemmay arise with regard to power control. For example, the base stationmay expect to receive a PH report containing a h(n_(CQI), n_(HARQ))value calculated for format 1, 1a or 1b from the mobile terminal.However, the mobile terminal may fail to receive PDSCH (PhysicalDownlink Shared Channel) information from the base station. In thiscase, the mobile terminal may send a PH report containing a h(n_(CQI),n_(HARQ)) value calculated for format 2, 2a or 2b to the base station.

To prevent such miscommunication, the mobile terminal may send a PHreport with h(n_(CQI), n_(HARQ))=0 to the base station whenever apredetermined condition for sending the PH report is met. That is,P_(PUCCH) may be calculated by Equation 13:P _(PUCCH)(i)=min{P _(CMAX) , P _(O) _(—) _(PUCCH) +PL+Δ _(F) _(—)_(PUCCH)(F)+g(i)}[dBm]  (13)

Alternatively, P_(PUCCH) may be calculated according to Equation 14,where Δ_(F) _(—) _(PUCCH)(F)=0, as follows:P _(PUCCH)(i)=min{P _(CMAX) , P _(O) _(—) _(PUCCH) +PL+g(i)}[dBm]  (14)

When the base station and mobile terminal agree to use P_(PUCCH)(i), asdefined by Equation 13 or Equation 14, in processing PH_(PUSCH+PUCCH),the base station may re-compute PH_(PUSCH+PUCCH) using PH_(PUSCH+PUCCH),and h(n_(CQI), n_(HARQ)) and Δ_(F) _(—) _(PUCCH)(F) expected by the basestation scheduler.

FIG. 6 is a diagram illustrating power headroom reporting according tothe second embodiment of the present invention.

Referring to FIG. 6, in the case where the LTE-Advanced system allowstransmission over both PUSCH and PUCCH in the same subframe, in responseto occurrence of an event requesting power headroom reporting, themobile terminal may report PH_(PUSCH) 606 and PH_(PUSCH+PUCCH) 607 tothe base station using Equations 12, 13 or 14. PH_(PUSCH+PUCCH) 607 isdetermined by subtracting the transmit power P_(PUSCH) 605 for PUSCHtransmission 602 calculated in subframe 4 and the transmit powerP_(PUCCH) 604 for PUCCH transmission 601 calculated in subframe 4 fromthe maximum transmit power according to the power class of the mobileterminal (P_(CMAX)). PUCCH transmission 601 is initially used for CQIinformation. The difference between P_(PUCCH) 304 of FIG. 3 andP_(PUCCH) 604 of FIG. 6 is that information as to P_(PUCCH) 604 relatedto PUCCH transmission 601 is obtained according to Equations 13 or 14.

FIG. 7 is a flow chart illustrating a procedure for power headroomreporting performed by a mobile terminal according to the secondembodiment of the present invention.

Referring to FIG. 7, the mobile terminal determines whether PUSCHtransmission and PUCCH transmission are allowed to occur in the samesubframe, in step 701. Permission for parallel transmission over bothPUSCH and PUCCH in the same subframe may be signaled from higher layersor the base station.

When PUSCH transmission and PUCCH transmission are not allowed to occurin the same subframe (i.e., PUSCH transmission and PUCCH transmissionmust occur in different subframes), the mobile terminal determineswhether an event requesting PH_(PUSCH) reporting is generated, in step707. When an event requesting PH_(PUSCH) reporting is generated, themobile terminal reports PH_(PUSCH) to the base station according toEquation 11, in step 708.

When PUSCH transmission and PUCCH transmission are allowed to occur inthe same subframe, the mobile terminal stores information regarding thetransmit power P_(PUCCH) for each time PUCCH transmission is performed,in step 702. Here, the transmit power P_(PUCCH) is calculated accordingto Equations 13 or 14.

The mobile terminal determines whether an event requestingPH_(PUSCH+PUCCH) reporting has been generated, in step 703. When anevent requesting PH_(PUSCH+PUCCH) reporting has not been generated, themobile terminal returns to step 702.

When an event requesting PH_(PUSCH+PUCCH) reporting is generated insubframe i, the mobile terminal checks whether PUCCH transmission ispresent in subframe i, in step 704.

When PUCCH transmission is present in subframe i, the mobile terminalreports PH_(PUSCH+PUCCH) and PH_(PUSCH) to the base station using thetransmit power P_(PUCCH)(i) for PUCCH transmission in subframe i, instep 705. Here, the transmit power P_(PUCCH)(i) may be calculated usingEquations 13 or 14.

When PUCCH transmission is not present in subframe i, the mobileterminal reports PH_(PUSCH+PUCCH) and PH_(PUSCH) to the base stationusing the stored transmit power P_(PUCCH) for the latest PUCCHtransmission, in step 709.

FIG. 8 is a flow chart of illustrating procedure for power headroomreporting performed by the base station according to the secondembodiment of the present invention.

Referring to FIG. 8, the base station determines whether the mobileterminal is allowed to conduct both PUSCH transmission and PUCCHtransmission in the same subframe, in step 801.

When the mobile terminal is allowed to conduct PUSCH transmission andPUCCH transmission in the same subframe, the base station receivesPH_(PUSCH+PUCCH) and PH_(PUSCH) from the mobile terminal in a subframewhere a corresponding event is generated, in step 802.

The base station determines whether both a PUSCH transmission and aPUCCH transmission from the mobile terminal are present or only a PUSCHtransmission is present in a scheduled subframe, in step 803.

When only a PUSCH transmission is present in the scheduled subframe, thebase station assigns MCS and M_(PUSCH) to the mobile terminal usingreported PH_(PUSCH), in step 804.

When both PUSCH transmission and PUCCH transmission are present in thescheduled subframe, the mobile terminal conducts PUSCH transmission andPUCCH transmission in the scheduled subframe, in step 808.

After the transmission of step 808, the base station assigns MCS andM_(PUSCH) to the mobile terminal using reported PH_(PUSCH+PUCCH), instep 809.

When it is determined that the mobile terminal is not allowed to conductPUSCH transmission and PUCCH transmission in the same subframe at step801, the base station receives PH_(PUSCH) from the mobile terminal, instep 806.

After the assignment of step 806, the base station assigns MCS andM_(PUSCH) to the mobile terminal in a scheduled subframe using reportedPH_(PUSCH), in step 807.

Third Embodiment of the Present Invention:

FIG. 9 is a diagram illustrating power headroom reporting according to athird embodiment of the present invention.

Referring to FIG. 9, when of transmitting two CodeWords (CW) CW #1 andCW #2, PH_(PUSCH+PUCCH)(CW #1) and PH_(PUSCH+PUCCH)(CW #2), the twocodewords may be separately reported according to Equation 15:PH _(PUSCH+PUCCH)(i, CW #1)=P _(CMAX) −P _(PUSCH)(i, CW #1)−P_(PUCCH)(i) [dB]PH _(PUSCH)(i, CW #1)=P _(CMAX) −P _(PUSCH)(i, CW #1) [dB]PH _(PUSCH+PUCCH)(i, CW #2)=P _(CMAX) −P _(PUSCH)(i, CW #2)−P_(PUCCH)(i)[dB]PH _(PUSCH)(i, CW #2)=P _(CMAX) −P _(PUSCH)(i, CW #2)[dB]  (15)

Power headroom reporting for each codeword may be necessary in thefollowing case. When two codewords CW #1 and CW #2 to be transmitted arepresent, CW #1 may be in the process of retransmission while CW #2 hasbeen successfully transmitted. In addition, when power control isperformed independently for individual codewords, power headroomreporting for each codeword may be necessary.

Referring to FIG. 2, in the case of the LTE-Advanced system allowingtransmission over both PUSCH and PUCCH in the same subframe, in responseto occurrence of an event requesting Power Headroom (PH) reporting, themobile terminal may report PH_(PUSCH)(CW #1) 907, PH_(PUSCH+PUCCH)(CW#1) 908, PH_(PUSCH)(CW #2) 909 and PH_(PUSCH+PUCCH)(CW #2) 910 to thebase station using Equation 15 on the basis of transmit power P_(PUCCH)905 of PUCCH transmission 902, transmit power P_(PUSCH)(CW #1) 906 ofPUSCH transmission 903 related to the codeword CW #1, and transmit powerP_(PUSCH)(CW #2) 904 of PUSCH transmission 901 related to the codewordCW #2.

As in Equation 15, PH_(PUSCH+PUCCH)(CW #1) 908 is determined bysubtracting the transmit power P_(PUSCH)(CW #1) 906 of PUSCHtransmission 903 related to the codeword CW #1 calculated in subframe iand the transmit power P_(PUCCH) 905 of PUCCH transmission 902 from themaximum transmit power according to the power class of the mobileterminal (P_(CMAX)). PH_(PUSCH+PUCCH)(CW #1) 910 is determined bysubtracting the transmit power P_(PUSCH)(CW #2) 904 of PUSCHtransmission 901 related to the codeword CW #2 calculated in subframe iand the transmit power P_(PUCCH) 905 of PUCCH transmission 902 from themaximum transmit power according to the power class of the mobileterminal (P_(CMAX)).

PH_(PUSCH)(CW #1) 907 is determined by subtracting the transmit powerP_(PUSCH)(CW #1) 906 of PUSCH transmission 903 related to the codewordCW #1 calculated in subframe i from the maximum transmit power accordingto the power class of the mobile terminal (P_(CMAX)). PH_(PUSCH)(CW #2)909 is determined by subtracting the transmit power P_(PUSCH)(CW #2) 904of PUSCH transmission 901 related to the codeword CW #2 calculated insubframe i from the maximum transmit power according to the power classof the mobile terminal (P_(CMAX)).

FIG. 10 is a flow chart illustrating a procedure for power headroomreporting performed by the mobile terminal according to the thirdembodiment of the present invention.

Referring to FIG. 10, the mobile terminal determines whether PUSCHtransmission for CW #1 and CW #2 and PUCCH transmission are allowed tooccur in the same subframe, in step 1001. Permission for paralleltransmission over both PUSCH and PUCCH in the same subframe may besignaled from higher layers or the base station.

When PUSCH transmission and PUCCH transmission are not allowed to occurin the same subframe (i.e., PUSCH transmission and PUCCH transmissionmust occur in different subframes), the mobile terminal determineswhether an event requesting PH_(PUSCH)(CW #1) and PH_(PUSCH)(CW #2)reporting has been generated, in step 1007. When an event requestingPH_(PUSCH)(CW #1) and PH_(PUSCH)(CW #2) reporting is generated, themobile terminal reports PH_(PUSCH)(CW #1) and PH_(PUSCH)(CW #2) to thebase station according to Equation 15, in step 1008.

When PUSCH transmission and PUCCH transmission are allowed to occur inthe same subframe, the mobile terminal stores information regarding thetransmit power P_(PUCCH) for each PUCCH transmission, in step 1002.

The mobile terminal determines whether an event requestingPH_(PUSCH+PUCCH)(CW #1) and PH_(PUSCH+PUCCH)(CW #2) reporting has beengenerated, in step 1003. When an event requesting PH_(PUSCH+PUCCH)(CW#1) and PH_(PUSCH+PUCCH)(CW #2) reporting has not been generated, themobile terminal returns to step 1002.

When an event requesting PH_(PUSCH+PUCCH)(CW #1) and PH_(PUSCH+PUCCH)(CW#2) reporting is generated in subframe i, the mobile terminal determineswhether PUCCH transmission is present in subframe I, in step 1004.

When PUCCH transmission is present in subframe i, the mobile terminalreports PH_(PUSCH+PUCCH)(CW #1), PH_(PUSCH+PUCCH)(CW #2), PH_(PUSCH)(CW#1) and PH_(PUSCH)(CW #2) to the base station using the transmit powerP_(PUCCH)(i) for PUCCH transmission in subframe i, in step 1005.

When a PUCCH transmission is not present in subframe i, the mobileterminal reports PH_(PUSCH+PUCCH)(CW #1), PH_(PUSCH+PUCCH)(CW #2),PH_(PUSCH)(CW #1) and PH_(PUSCH)(CW #2) to the base station using thestored transmit power P_(PUCCH) for the latest PUCCH transmission, instep 1009.

Fourth to sixth embodiments of the present invention, which are relatedto per-layer power control, are described as follows.

Fourth Embodiment of the Present Invention:

For per-layer power control, the base station may signal precodingmatrices and differences between powers of layers to the mobileterminal. The base station determines the number of ranks and precodingmatrices that maximize the channel capacity of the uplink on the basisof Sounding Reference Signals (SRS) from the mobile terminal andcodebooks. When one codeword is mapped to two layers, the base stationsignals information regarding powers assigned to the two layers to themobile terminal. Here, powers may be assigned to the two layersaccording to SINR (signal to interference-plus-noise ratio) equality(i.e., SINR of one layer equals that of the other layer) or according tochannel quality (i.e., assigning more power to one layer having higherchannel quality, like water filling). For example, when the base stationdetermines the number of ranks for the mobile terminal to be three,codeword CW #1 of the mobile terminal is mapped to layer #1 and codewordCW #2 is mapped to layer #2 and layer #3. In addition to precodingmatrix information, the base station provides information on the powerdifference between layer #2 and layer #3 to the mobile terminal. Forexample, two bits may be used to represent four values [−3, −1, 1, 3]dB. When the base station signals −3 dB, the mobile terminal sets thetransmit power of layer #3 to −3 dB of the transmit power of layer #2.

In addition to [−3, −1, 1, 3], other cases such as [−6, −3, 3, 6] and[−3, −1, 0, 1] may be considered. For a rank 3 transmission, when fourbits are used to represent 16 precoding matrices and two bits are usedto represent power differences between the layers, the base stationprovides a total of six bits of information to the mobile terminal.

Fifth Embodiment of the Present Invention:

Table 1 illustrates cases in which a single codeword may be mapped totwo layers. Referring to Table 1, when there is one codeword and twolayers, CW #1 is mapped to layer #1 and layer #2. In order to representand signal four power differences [−3, −1, 1, 3] dB between layer #1 andlayer #2, two bits are necessary. In the case where two codewords aremapped to three layers, CW #2 is mapped to layer #2 and layer #3, andtwo bits are necessary to represent power differences between layer #2and layer #3. In the case where two codewords are mapped to four layers,as CW #1 is mapped to layer #1 and layer #2, CW #2 is mapped to layer #3and layer #4, and two bits are necessary to represent power differencesbetween layer #1 and layer #2 and two bits are necessary to representpower differences between layer #3 and layer #4.

TABLE 1 Number of bits to Number represent transmit power Number of ofdifferences between two codewords layers Layer mapping layers 1 2 Map CW#1 to layer 2 bits #1 and layer #2 2 3 Map CW #1 to layer 0 bit #1 MapCW #2 to layer 2 bits #2 and layer #3 2 4 Map CW #1 to layer 2 bits #1and layer #2 Map CW #2 to layer 2 bits #3 and layer #4

FIG. 11 is a flow chart illustrating a procedure for per-layer powercontrol performed by the base station according to the fifth embodimentof the present invention.

Referring to FIG. 11, the MCS scheduler of the base station determinesthe number of ranks and precoding matrices that maximize the channelcapacity of the uplink on the basis of SRS information from the mobileterminal and codebooks, in step 1101.

The base station determines whether one codeword is mapped to twolayers, in step 1102.

When one codeword is mapped to two layers, the base station assignspowers to the two layers so that the two layers have the same SINR valueor by allocating more power to one layer having higher channel quality(such as according to a water filling algorithm), in step 1103.

The base station signals information on the precoding matrices andinformation on power differences between the layers to the mobileterminal, in step 1104.

When one codeword is not mapped to two layers, the base station outputssignals including information regarding the precoding matrices and thepower difference between layers set to 0 dB to the mobile terminal, instep 1105.

Sixth Embodiment of the Present Invention:

Table 2 illustrates cases in which each of two codewords may be mappedto two layers.

TABLE 2 Number Number Number of bits to represent of of transmit powerdifferences codewords layers Layer mapping between two layers 2 3 Map CW#1 to 4 bits: 2 bits for power layer #1 differences between layer #1 MapCW #2 to and layer, and 2 bits for power layer #2 and differencesbetween layer #1 layer #3 and layer #3 (relative to layer #1) 2 4 Map CW#1 to 6 bits: 2 bits for power layer #1 and differences between layer #1layer #2 and layer #2, 2 bits for power Map CW #2 to differences betweenlayer #1 layer #3 and and layer #3, and 2 bits for layer #4 powerdifferences between layer #1 and layer #4 (relative to layer #1)

Referring to Table 2, in a case where two codewords are mapped to threelayers, CW #1 is mapped to layer #1 and CW #2 is mapped to layer #2 andlayer #3. Four bits are necessary if two bits are allocated to representpower differences between layer #1 and layer #2 and two bits areallocated to represent power differences between layer #1 and layer #3.In a case where two codewords are mapped to four layers, CW #1 is mappedto layer #1 and layer #2 and CW #2 is mapped to layer #3 and layer #4.Six bits are necessary in a case where two bits are allocated torepresent power differences between layer #1 and layer #2, two bits areallocated to represent power differences between layer #1 and layer #3,and two bits are allocated to represent power differences between layer#1 and layer #4.

FIG. 12 is a flow chart illustrating a procedure for per-layer powercontrol performed by the base station according to the sixth embodimentof the present invention.

Referring to FIG. 12, the base station determines a number of ranks andprecoding matrices that maximize the channel capacity of the uplink onthe basis of SRS information from the mobile terminal and codebooks, instep 1201.

The base station determines whether two codewords are mapped to three ormore layers, in step 1202. When two codewords are mapped to three ormore layers, the base station assigns powers to the layers so that thelayers have the same SINR value or allocates more power to layers thathave higher channel qualities (such as according to a water fillingalgorithm), in step 1203.

The base station outputs signals including information regarding theprecoding matrices and information regarding power differences betweenthe layers to the mobile terminal, in step 1204.

When two codewords are mapped to less than three layers, the basestation outputs signals including information regarding the precodingmatrices and the power difference between layers set to 0 dB to themobile terminal, in step 1205.

Seventh Embodiment of the Present Invention

According to the first embodiment of the present invention, when a PUCCHtransmission is not present in a subframe, the stored transmit powerP_(PUCCH) of the latest PUCCH transmission is utilized. According to thesecond embodiment of the present invention, in order to prevent aproblem in power control caused by different h(n_(CQI), n_(HARQ)) valuesdepending on PUCCH formats, the mobile terminal sends a PH report withh(n_(CQI), n_(HARQ))=0 or Δ_(F) _(—) _(PUCCH)(F)=0 to the base station,i.e., when the base station and mobile terminal agree to useP_(PUCCH)(i) according to Equation 13 or Equation 14 in processingPH_(PUSCH+PUCCH), the base station may re-compute PH_(PUSCH+PUCCH) usingPH_(PUSCH+PUCCH), and h(n_(CQI), n_(HARQ)) and Δ_(F) _(—) _(PUCCH)(F)expected by the base station scheduler.

The seventh embodiment of the present invention is an extension of thefirst and second embodiments of the present invention. According to theseventh embodiment of the present invention, when δ_(PUCCH) values (forexample, [−1, 0, 1, 3] or [−1, 1]) are signaled to the mobile terminalthrough a PDCCH with DCI format 3/3A, g(i), such as in Equations 13 or14, is updated using the δ_(PUCCH) values signaled on PDCCH with DCIformat 3/3A.

FIG. 13 is a diagram illustrating power headroom reporting according tothe seventh embodiment of the present invention.

Referring to FIG. 13, in a case where the LTE-Advanced system allowstransmission over both PUSCH and PUCCH in the same subframe, in responseto occurrence of an event requesting power headroom reporting, themobile terminal may report PH_(PUSCH) 1306 and PH_(PUSCH+PUCCH) 1307 tothe base station according to Equations 12, 13 and 14. The seventhembodiment of the present invention differs from the second embodimentof the present invention in that, according to the seventh embodiment ofthe present invention, when δ_(PUCCH) 1308 is signaled on PDCCH with DCIformat 3/3A, the mobile terminal uses δ_(PUCCH) 1308 signaled on PDCCHwith DCI format 3/3A to calculate g(i) 1309 and computes the transmitpower P_(PUCCH) 1304 according to Equations 13 and 14.

PH_(PUSCH+PUCCH) 1307 is determined by subtracting the transmit powerP_(PUSCH) 1305 for PUSCH transmission 1302 calculated in subframe 4 andthe transmit power P_(PUCCH) 1304 from the maximum transmit poweraccording to the power class of the mobile terminal (P_(CMAX)). Incomputation of P_(PUCCH) 1304, the latest PUCCH transmission 1301 isused, h(n_(CQI), n_(HARQ))=0 and Δ_(F) _(—) _(PUCCH)(F)=0 are used inEquations 13 and 14, and δ_(PUCCH) 1308 is used to calculate g(i) 1309.

Eighth Embodiment of the Present Invention:

According to the second embodiment of the present invention, in order toprevent a problem in power control caused by different h(n_(CQI),n_(HARQ)) values depending on PUCCH formats, the mobile terminal sends aPH report with h(n_(CQI), n_(HARQ))=0 or Δ_(F) _(—) _(PUCCH)(F)=0(Equation 14) to the base station.

By contrast, according to the eighth embodiment of the presentinvention, in order to prevent a problem in power control that may becaused by a difference between the PUCCH format expected by the basestation and the PUCCH format actually used by the mobile terminal, themobile terminal sends a PH report with 3-bit indication to the PUCCHformat (e.g., 1, 1a, 1b, 2, 2a and 2b) to the base station.

Although embodiments of the present invention have been described indetail hereinabove, it should be understood that many variations andmodifications of the basic inventive concept herein described, which mayappear to those skilled in the art, will still fall within the spiritand scope of the embodiments of the present invention as defined in theappended claims.

What is claimed is:
 1. A method of reporting power headroom for a userequipment (UE) to a base station, the method comprising: obtaining powerheadroom information by subtracting a first value associated withphysical uplink shared channel (PUSCH) and physical uplink controlchannel (PUCCH) transmit power from a second value associated with amaximum UE transmit power in a subframe, if a simultaneous PUCCH andPUSCH transmission is allowed; and transmitting the power headroominformation to the base station, wherein the first value is obtainedbased on nominal PUCCH power information, UE PUCCH power information,path-loss information, and information based on power controlinformation, if the UE transmits a PUSCH without a PUCCH in the subframeand wherein the nominal PUCCH power information is a cell-specificparameter provided by higher layers, and the UE PUCCH power informationis a UE-specific parameter provided by radio resource control (RRC)signaling.
 2. The method of claim 1, wherein the first value is obtainedbased on the nominal PUCCH power information, the UE PUCCH powerinformation, a value associated with a PUCCH format provided by the RRCsignaling, the path-loss information, a PUCCH format dependent value,and the information based on the power control information transmittedby the UE, if the UE transmits the PUSCH with the PUCCH in the subframe.3. The method of claim 2, wherein, if the UE transmits the PUSCH withthe PUCCH in the subframe, the first value is a sum of a valueassociated with the PUSCH transmit power and a value associated with thePUCCH transmit power, and the value associated with the PUCCH transmitpower is based on:P _(o) _(—) _(PUCCH)+PL+h(n _(CQI) ,n _(HARQ))+Δ_(F) _(—)_(PUCCH)(F)+g(i), where P_(o) _(—) _(PUCCH) is a sum of the nominalPUCCH power information P_(o) _(—) _(NOMINAL) _(—) _(PUCCH) and the UEPUCCH power information P_(o) _(—) _(UE) _(—) _(PUCCH), Δ_(F) _(—)_(PUCCH)(F) is the value associated with the PUCCH format provided bythe RRC signaling, PL is the path-loss information, h(n_(CQI),n_(HARQ))is the PUCCH format dependent value, and g(i) is the information basedon the power control information transmitted by the UE.
 4. The method ofclaim 1, further comprising: receiving the power control informationused for obtaining the power headroom information.
 5. The method ofclaim 1, further comprising: receiving simultaneous PUCCH and PUSCHtransmission information indicating whether the simultaneous PUCCH andPUSCH transmission is allowed or not via higher layer signaling.
 6. Amethod of receiving a power headroom report for a base station from auser equipment (UE), the method comprising: transmitting power controlinformation used for obtaining power headroom information; receiving thepower headroom information obtained by subtracting a first valueassociated with physical uplink shared channel (PUSCH) and physicaluplink control channel (PUCCH) transmit power from a second valueassociated with a maximum UE transmit power in a subframe, if asimultaneous PUCCH and PUSCH transmission is allowed, wherein the firstvalue is obtained based on nominal PUCCH power information, UE PUCCHpower information, path-loss information, and information based on thepower control information, if the UE transmits a PUSCH without a PUCCHin the subframe and wherein the nominal PUCCH power information is acell-specific parameter provided by higher layers, and the UE PUCCHpower information is a UE-specific parameter provided by radio resourcecontrol (RRC) signaling.
 7. The method of claim 6, wherein the firstvalue is obtained based on the nominal PUCCH power information, the UEPUCCH power information, a value associated with a PUCCH format providedby the RRC signaling, the path-loss information, a PUCCH formatdependent value, and the information based on the power controlinformation transmitted by the UE, if the UE transmits the PUSCH withthe PUCCH in the subframe.
 8. The method of claim 7, wherein, if the UEtransmits the PUSCH with the PUCCH in the subframe, the first value is asum of a value associated with the PUSCH transmit power and a valueassociated with the PUCCH transmit power, and the value associated withthe PUCCH transmit power is based on:P _(o) _(—) _(PUCCH)+PL+h(n _(CQI) ,n _(HARQ))+Δ_(F) _(—)_(PUCCH)(F)+g(i), where P_(o) _(—) _(PUCCH) is a sum of the nominalPUCCH power information P_(o) _(—) _(NOMINAL) _(—) _(PUCCH) and the UEPUCCH power information P_(o) _(—) _(UE) _(—) _(PUCCH), Δ_(F) _(—)_(PUCCH)(F) is the value associated with the PUCCH format provided bythe RRC signaling, PL is the path-loss information, h(n_(CQI),n_(HARQ))is the PUCCH format dependent value, and g(i) is the information basedon the power control information transmitted by the UE.
 9. The method ofclaim 6, further comprising: transmitting simultaneous PUCCH and PUSCHtransmission information indicating whether the simultaneous PUCCH andPUSCH transmission is allowed or not via higher layer signaling.
 10. Auser equipment (UE) apparatus for reporting power headroom to a basestation, the UE apparatus comprising: a transceiver configured totransmit and receive signals to and from the base station, wherein theUE apparatus is configured to obtain power headroom information bysubtracting a first value associated with physical uplink shared channel(PUSCH) and physical uplink control channel (PUCCH) transmit power froma second value associated with a maximum UE transmit power in asubframe, if a simultaneous PUCCH and PUSCH transmission is allowed, andtransmit the power headroom information to the base station, wherein thefirst value is obtained based on nominal PUCCH power information, UEPUCCH power information, path-loss information, and information based onpower control information, if the UE transmits a PUSCH without a PUCCHin the subframe and wherein the nominal PUCCH power information is acell-specific parameter provided by higher layers, and the UE PUCCHpower information is a UE-specific parameter provided by radio resourcecontrol (RRC) signaling.
 11. The UE apparatus of claim 10, wherein thefirst value is obtained based on the nominal PUCCH power information,the UE PUCCH power information, a value associated with a PUCCH formatprovided by the RRC signaling, the path-loss information, a PUCCH formatdependent value, and the information based on the power controlinformation transmitted by the UE, if the UE transmits the PUSCH withthe PUCCH in the subframe.
 12. The UE apparatus of claim 11, wherein, ifthe UE transmits the PUSCH with the PUCCH in the subframe, the firstvalue is a sum of a value associated with the PUSCH transmit power and avalue associated with the PUCCH transmit power, and the value associatedwith the PUCCH transmit power is based on:P _(o) _(—) _(PUCCH)+PL+h(n _(CQI) ,n _(HARQ))+Δ_(F) _(—)_(PUCCH)(F)+g(i), where P_(o) _(—) _(PUCCH) is a sum of the nominalPUCCH power information P_(o) _(—) _(NOMINAL) _(—) _(PUCCH) and the UEPUCCH power information P_(o) _(—) _(UE) _(—) _(PUCCH), Δ_(F) _(—)_(PUCCH)(F) is the value associated with the PUCCH format provided bythe RRC signaling, PL is the path-loss information, h(n_(CQI),n_(HARQ))is the PUCCH format dependent value, and g(i) is the information basedon the power control information transmitted by the UE.
 13. The UEapparatus of claim 10, wherein the UE apparatus is further configured toreceive the power control information used for obtaining the powerheadroom information.
 14. The UE apparatus of claim 10, wherein the UEapparatus is further configured to receive simultaneous PUCCH and PUSCHtransmission information indicating whether the simultaneous PUCCH andPUSCH transmission is allowed or not via higher layer signaling.
 15. Abase station apparatus for receiving a power headroom report from a userequipment (UE), the base station apparatus comprising: a transceiverconfigured to transmit and receive signals to and from the UE; and acontroller configured to transmit power control information used forobtaining power headroom information, and receive the power headroominformation obtained by subtracting a first value associated withphysical uplink shared channel (PUSCH) and physical uplink controlchannel (PUCCH) transmit power from a second value associated with amaximum UE transmit power in a subframe, if a simultaneous PUCCH andPUSCH transmission is allowed, wherein the first value is obtained basedon nominal PUCCH power information, UE PUCCH power information,path-loss information, and information based on the power controlinformation, if the UE transmits a PUSCH without a PUCCH in the subframeand wherein the nominal PUCCH power information is a cell-specificparameter provided by higher layers, and the UE PUCCH power informationis a UE-specific parameter provided by radio resource control (RRC)signaling.
 16. The base station apparatus of claim 15, wherein the firstvalue is obtained based on the nominal PUCCH power information, the UEPUCCH power information, a value associated with a PUCCH format providedby the RRC signaling, the path-loss information, a PUCCH formatdependent value, and the information based on the power controlinformation transmitted by the UE, if the UE transmits the PUSCH withthe PUCCH in the subframe.
 17. The base station of claim 16, wherein, ifthe UE transmits the PUSCH with the PUCCH in the subframe, the firstvalue is a sum of a value associated with the PUSCH transmit power and avalue associated with the PUCCH transmit power, and the value associatedwith the PUCCH transmit power is based on:P _(o) _(—) _(PUCCH)+PL+h(n _(CQI) ,n _(HARQ))+Δ_(F) _(—)_(PUCCH)(F)+g(i), where P_(o) _(—) _(PUCCH) is a sum of the nominalPUCCH power information P_(o) _(—) _(NOMINAL) _(—) _(PUCCH) and the UEPUCCH power information P_(o) _(—) _(UE) _(—) _(PUCCH), Δ_(F) _(—)_(PUCCH)(F) is the value associated with the PUCCH format provided bythe RRC signaling, PL is the path-loss information, h(n_(CQI),n_(HARQ))is the PUCCH format dependent value, and g(i) is the information basedon the power control information transmitted by the UE.
 18. The basestation of claim 15, wherein the controller is further configured totransmit simultaneous PUCCH and PUSCH transmission informationindicating whether the simultaneous PUCCH and PUSCH transmission isallowed or not via higher layer signaling.
 19. A system for reportingpower headroom, the system comprising: a base station configured totransmit power control information used for obtaining power headroominformation, and receive the power headroom information; and a UserEquipment (UE) apparatus configured to obtain the power headroominformation by subtracting a first value associated with physical uplinkshared channel (PUSCH) and physical uplink control channel (PUCCH)transmit power from a second value associated with a maximum UE transmitpower in a subframe, if a simultaneous PUCCH and PUSCH transmission isallowed, and transmit the power headroom information to the basestation, wherein the first value is obtained based on nominal PUCCHpower information, UE PUCCH power information, path-loss information,and information based on the power control information, if the UEtransmits a PUSCH without a PUCCH in the subframe and wherein thenominal PUCCH power information is a cell-specific parameter provided byhigher layers, and the UE PUCCH power information is a UE-specificparameter provided by radio resource control (RRC) signaling.